Method of assembling t-shaped fasteners to webbing strips



June 19, 1962 H. KRAMER 3,039,184

METHOD OF ASSEMBLING TSHAPED FASTENERS TO WEBBING STRIPS 2 Sheets-Sheet 1 Filed April 17, 1959 4 INVENTOR HYMAN KRAMER ATTORNEY June 19, 1962 H, KRAMER 3,039,184.

METHOD OF ASSEMBLING T-SHAPED FASTENERS TO WEBBING STRIPS Filed April 17, 1959 2 Sheets-Sheet 2 INVENTOR. HYMAN KRAMER 4 ATTORNEY snsansa METHGD OF ASSEMBLING T-SHARED FASTENERS T WEBBING STRIPS Hyman Kramer, 2764 E. 16th St, Brooklyn, N.Y. Filed Apr. 17, 1959, Ser. No. 807,243 7 Claims. ((31. 29-417) This invention relates to the manufacture of tubular frame furniture, and is more particularly directed to a method of preassembling the fasteners which ultimately secure the ends of the webbing strips making up the back and/or seat elements of such furniture to the tubular framing thereof to the ends of measured lengths of webbing strip coming from a roll thereof, thus enabling the production in quantity of measured lengths of webbing strip with fasteners attached, ready for final fastening to the tubular framing.

Heretofore, it has been the practice to manually apply the fasteners to precut webbing strips during the course of a conveyor line operation of fastening the strips to the tubular frame, which operation required a first operator on one side of the line to pick up a fastener, apply it by a procedure dictated by its structure to one end of a webbing strip laid across the frame, and thereupon engage said fastener with the frame tubing, all by hand; and a second operator on the other side of the line performing similar operations on the other end of the strip to secure same to the opposite tubing. In large measure, such a laborious and time-consuming method of assembly was forced upon the industry by the lack of a fastener Whose construction was such as to make possible or feasible its assembly to the ends of the precut webbing strips prior to said strips being related to the tubular frame moving along the conveyor line as aforesaid.

Quite recently, however, I devised a family of webbing strip-to-tubing fastenings based on various forms of a socalled driveor push-type of fastener all characterized by general T-configuration, the vertical leg of which, when passed through the webbing strip end and forced into the tubing slot or opening provided therefor, was adapted to self-lock itself to the under-edges of the lips of said slot, such fastening and the fasteners employed therein being disclosed and claimed in my prior filed applications as follows: Serial No. 721,233, filed March 13, 1958, now Patent Number 2,978,775; Serial No. 763,951, filed September 25, 1958, now Patent Number 2,979,119; Serial No. 782,817, filed December 24, 1958; Serial No. 784,- 186, filed December 31, 1958; and Serial No. 784,280, filed December 31, 1958. While most if not all of the fasteners disclosed in my aforesaid applications lend themselves to being preassembled to the ends of precut webbing strips, one such fastener in particular, namely the T-fastener whose vertical leg terminates in a point shaped as an arrowhead whose barbs or fiukes are offset to opposite sides thereof, thus to automatically self-lock to both side-edge lips of the tubing slot when forced thereinto, according to my aforesaid application Serial No. 784,280 has been found in practice not only to be admirably suited to being preassembled to the ends of precut webbing strips, but also, and more importantly, to make possible high-speed production in quantity of webbing strip and fastener-attached assemblies or units ready for fastening to the furniture framing by an automated or fully mechanized procedure, as results in substantial reduction in the labor costs heretofore entailed in metal frame furniture manufacture, as well as in a substantial speed-up in such manufacture.

Thus, broadly stated, the present invention contemplates and provides an automated method of producing in quantity predetermined lengths of webbing strip with fasteners attached ready for simple attachment to the States Patent tubular framing of metal frame furniture as required from a continuous length of webbing strip supplied in roll form, for example, and individual fasteners feeding thereto from a source of supply thereof such as a hopper.

More particularly, the invention aims to provide a fully automated method of producing in quantity proper lengths of webbing strip with fasteners attached to the ends thereof as constitute complete webbing strip units ready for securement to furniture framing as aforesaid, wherein the fasteners are of the type having a drive or push-type attaching leg terminating in a point and are assembled to the webbing strip ends by forcing said leg through the material making up the same, but in such a manner as avoids any substantial weakening of the webbing strips in the area or zone thereof punctured by passage of said leg.

To more fully explain the import of the latter objective, webbing strip as conventionally employed in metal frame furniture manufacture has relatively narrow width and is usually of woven construction, and thus is subject to weakening as a result of severance of the warp and/or weft threads making up the same when a hole is cut therein by a punching or slitting tool, for example, or when the pointed end of a fastener attaching leg is driven through such webbing strip material at high speed, the degree of weakening of course depending generally on the number of threads severed.

Thus, it is a further important object of the invention, particularly when working with webbing strip material likely to be weakened to a substantial or even an appreciable extent as a consequence of forcing the fastener point through same automatically and at high speeds to make provision for so preparing or conditioning the webbing strip in advance of said point moving through same as insures against said fastener point seriously damaging or 'weakening the webbing strip as aforesaid.

More specifically, it is an object of the invention to provide a method of producing in quantity measured lengths of webbing strip having fasteners secured to the ends thereof by virtue of their fastener legs projecting through the material of said strips, characterized in that preparation is made for the passage of a fastener leg therethrough by spreading apart the warp and/or weft threads making up said webbing strip material sufficiently as to form a definable hole for said fastener leg, as distinguished from cutting or punching the material as results in undesirable thread severance.

Yet another object of the invention is the provision of a method of producing from a continuous length of webbing strip and a supply of individual fasteners of the type suitable for securing lengths of webbing strip to the tubular framing of metal frame furniture a succession of measured lengths of webbing strip, each having a fastener attached to the ends thereof by having a fastener leg driven or pushed through the material of said webbing strip, wherein the holes through which the fastener legs pass which are so constructed as to reduce the possibility of the webbing strip being weakened thereby.

The above and other objects of the invention and their manner of attainment will appear from the following detailed description, reference being had to the accompanying drawing wherein- FIG. 1 is a broken-away diagrammatic perspective view illustrating one method of producing from continuous webbing strip and individual fastener elements a succession of measured lengths of webbing strip having a fastener attached adjacent each 'end thereof, the view also generally illustrating the manner in which holes or apertures for passage of the fastener legs are formed in the material of the webbing strip without weakening the same as by severing the warp and/ or weft threads thereof;

FIG. 2 is a broken-away front diagrammatic view 3 further illustrating the aforesaid method and which additionally indicates the manner of forcing the fasteners through the webbing strip;

FIG. 3 is a view to FIG. 2 but illustrating a modified method of relating the fasteners to a length of webbing strip;

FIGS. 4 and 5 are views similar to FIGS. 2 and 3 but illustrating an alternate method to that illustrated in FIG. 1 for producing a succession of measured lengths of webbing strip having fasteners attached to both ends thereof, according to the invention.

FIG. 6 is a perspective view illustrating a preferred form of fastener employed in the practice of the instant method; and

FIG. 7 is an enlarged view of a length of webbing strip having a hole formed therein for the reception of a fastener according to the invention.

Referring to the drawings which diagrammatically illustrate various apparatus employed in the practice of and certain steps of the methods according to the invention, reference character A designates a continuous strip of webbing of the type conventionally employed in making up the seat and/ or back elements of metal frame furniture, which is being drawn or otherwise unwound from a roll supply R thereof. It wil be een that the strip is feeding from left to right in a generally horizontal path and, as proposed herein, it is given a step-by-step motion which is such as to advance the strip during each period of its motion a predetermined amount corresponding to the length of webbing strip then being prepared for use.

In progressing along its aforesaid path of movement, the continuous strip A travels beneath a transversely disposed knife blade B which has a normal raised position but which lowers during each interval that the strip A is at rest, and in so doing will sever the most advanced measured length of the strip. Thus, it will be observed that the so far described procedure results in the production of a succession of measured lengths of webbing strip being severed from the continuous strip A as the latter is drawn from the roll supply thereof.

As above forecast, the instant invention contemplates a fully automatic, high-speed method of applying to both ends of each of the succession of measured lengths of webbing strip being produced the fasteners which ultimately secure said strips to the tubing constituting the frame of the metal frame furniture, thus greatly simplifying the manufacture thereof by supplying preassembled webbing strips and fasteners attached thereto ready for direct application to said framing. The fasteners to be applied to the Webbing strip ends are preferably of the type shown in FIG. 6, which is substantially the fastener disclosed and claimed in my aforesaidco-pending application Serial No. 784,280. Briefly, such a fastener designated F herein is formed from sheet metal to general 'T-configuration and is principally characterized by its strap-like vertical leg or prong 10 which has appreciable width as compared to its thickness being struck from the material of the head or cross bar 12 of the T and terminating at its free end in a driving point 14 of arrowhead shape whose barbs or flukes 14a, 14b project beyond the side edges of the leg proper and are offset to the general plane of said point. Apart from its use in the present method, such a fastener possesses numerous practical advantages for use in securing webbing strips to tubular metal framing, principal among which is that it lends itself to manufacture in quantity at relatively low cost; it is adapted when assembled to the webbing strip end to attach itself thereto with sufiicient security as prevents its being dislodged or shaken loose therefrom in normal handling of the webbing strips prior to their securement to the tubular framing; and, by 'virtue of its driving point having arrowhead configuration with offset barbs, it is capable of self-locking itself to the under edges of the lips defining the tubing opening with which the barbs 14a, 14b engage when the leg is pressed into said opening. In addition to its aforesaid general advantages, such a fastener lends itself to being preassembled to webbing strip ends by the automated method to be described, for reasons which will appear as the description of said method proceeds.

As diagrammatically illustrated in FlGS. 1 and 2, the fasteners F to be assembled are fed from a hopper or hoppers (not shown) to a pair of chutes C-ll, C-Z whose respective delivery ends extend transversely across and are slightly raised from the length of webbing strip A being worked upon. According to the FIGS. 1 and 2 method, the chute C-l is disposed a short distance forwardly from the knife B and hence from the line of severance which determines one (the rearward) end edge of the most advanced measured length of webbing strip upon its severance, as ultimately results in the fastener F being applied to said measured length at a point which is set back a short distance from said edge as provides for the desirable underlap of webbing strip end in the final fastening, all as disclosed in my aforesaid applications and particularly Serial No. 784,280. Also the chute C-Z is disposed at corresponding distance rearwardly of said line of severeance, thus to position the fastener to be applied to the next advancing measured length of webbing strip at a point which is set back a corresponding distance from the forward edge of said next advancing length as provides the desirable underlap of webbing strip end in the final fastening which it makes.

Upon the endmost fasteners F then on the chutes C1 and C2 being disposed over the webbing strip in proper position as to be applied thereto, fastener driving means, such as the diagrammatically shown air hammers 1-1-1 and H2 (FIG. 2) will lower against said endmost fasteners and force their driving points as provided by the arrow-shaped ends of the vertical legs 14 thereof through the webbing trip, thus to effect preassembly of the fasteners therewith. The air hammers 1-1-1 and H4. preferably operate in synchronism with each other and desirably also in synchronism with the cut-off blade B. Thus it will be seen that with each operation of cutting off the most advanced measured length of webbing strip, a fastener F is applied to the relatively rear-end portion thereof, and simultaneously therewith a fastener is similarly applied to the relatively forward end of the next rearward length of webbing strip to be severed in the next severing operation.

While the structural details of the chutes C-1 and 0-2 have been only generally described, it will be observed that said chutes preferably have upwardly opening chan nel-section as shown, and that the bottom wall of each channel is longitudinally slotted as at 20 to accommodate the vertical legs of the fasteners as the latter, supported from their head or cross-bars 12, are intermittently moved down the chute to their endmost or assembly-ready position over the webbing strip. Moreover, to provide a passage through the channel bottom for the length portion thereof on which said endmost fasteners are supported, thus to permit said fasteners to move downwardly from the chute when engaged by the air hammers H-il, H4, preferably the bottom-wall sections 22, 24 of the chute channel, for the length portion thereof on which the endrnost fasteners F are supported, are hingedly connected to the corresponding vertical walls 22, 24 of the channel as by piano hinges 26, 2,8, which permit said bottom-wall sections to swing downwardly-outwardly upon application of a predetermined force thereon. Normally, however, said bottom-wall sections 22, 24 are biased to their horizontal position in which they have been illustrated by spring means not shown, but which is preferably incorporated into said hinge structure.

While attachment of the fasteners F to the webbing strip ends as entailed in the above procedure would be facilitated if precut holes were provided therein to receive said fastener legs, either by slitting or punching same, it was early found that the provision of said holes was likely to seriously weaken webbing strip having the relatively narrow width as conventionally employed in metal frame furniture, due to said holes severing a multiplicity of the warp and/ or weft threads making up woven webbing strip, and similarly of cutting through the numerous fibers of the webbing strip material in the event the latter was of plastic, non-woven construction. It also became evident that when the driving points of arrowhead configuration characterizing the fasteners F were driven at a high rate of speed through the material of the conventional webbing strip such could also result in an undesirable severance of the threads and/or fibers making up the same.

According to the present method, these difficulties have been satisfactorily overcome by the procedure now to be described of preparing the webbing strip material for the reception of the driving points of the vertical legs of the fasteners, as facilitates high-speed passage of said points therethrough with the minimum of severance of either or both the warp and weft threads and/ or fibers making up the material of said webbing strip. More particularly, and referring first to FIG. 1 and then to FIG. 7, there is provided a pair of plungers P-1, P-2 disposed to the opposite sides of the webbing strip A from the chutes C-ll, C-2 and in alignment with the attaching legs of the two endmost fastener elements then positioned on said chutes in their final or assembly-ready positions. Illustratively, the upper ends of said plungers have pointed ends appropriately shaped to first puncture and then widen out the hole which they make in the webbing strip material, and they are adapted to be reciprocated throughout working and retracting strokes by means not shown. In moving throughout their working stroke, the pointed upper ends of the plungers move against the under face of the webbing strip with sufiicient force as to penetrate same, and, consequent to their shaping, said ends proceed to widen their holes in the webbing strip material (if the latter is of woven construction) by displacing either or both the warp and weft threads making up the same rather than by severing said threads. Such is generally illustrated in FIG. 7 wherein it will be seen that a hole formed by one of said plungers is defined by some lateral displacement in opposite directions of a plurality of the warp threads X of the material and a corresponding but somewhat lesser opposite longitudinal displacement of the weft threads Y. In any event, the holes formed by the pointed ends of the plungers P-l, P.?. are not defined by the severed ends of the threads or fibers making up the material as would be the case if the holes were formed by punching or slitting tools, for example.

Preferably, the aforesaid slot 20 in the bottom wall of each chute channel is enlarged as at 2th: to accommodate the pointed ends of the plungers moving upwardly through the webbing strip. Also, to firm the material of the webbing strip in the general area affected by each of the plungers moving against the same, reciprocating presser feet L-l and L-2 are provided, one per chute and plunger assembly, such having a normally retracted position to the viewers side of the advancing webbing strip A, but being movable on its working stroke to an active position as shown in which it is disposed intermediate an associated chute and the upper surface of the strip, and close to the latter. When so positioned, the presser feet L serve to prevent bellyin g or stretching of the webbing strip material acted on by the Working ends of the plungers and accordingly make for a cleaner hole being formed by said plungers. It will be understood that the presser feet retract to their aforesaid inactive position prior to the fastener driving means lowering on the endmost fasteners.

It is a further feature of the invention that the pneumatic hammers I-I-l, H-2 are timed to initiate their action on the endmost fasteners in the assembly-ready position on the chutes C-1, C2 at about the same instant that the plungers P-1, P-2 begin their retracting movement. Accordingly, assuming that the pointed ends of the plungers after piercing the webbing strip come in to close proximity with the pointed ends of the fastener legs, such timing provides for the plungers leading the fastener legs through the holes in the webbing strip and thus facilitate application of the fasteners prior to the holes closing up to any substantial extent as the plungers retract therefrom.

Referring to FIG. 3, such is illustrative of a somewhat modified procedure of applying the fasteners. More particularly, the FIG. 3 method illustrates the alternate procedure of applying the fasteners to both ends of the most advanced length of webbing strip simultaneously, and preferably also simultaneously with the cutting of said most advanced length from the next following length. In the practice of the modified method, the chutes C-1, C2 and their associated plungers P-1, P-2 are disposed relatively forwardly of the cutting blade B, with the chute C-1 and associated plunger P-1 being disposed a short distance rearwardly from the forward end edge of the most advanced length and the chute C-2 and its associated plunger P-Z being positioned a similar distance forwardly from the rearward end of said most advanced length. Of course it will be understood that the ultimate product of the alternate method according to FIG. 3 is identical with that of the product of the FIGS. 1 and 2 method.

FIGS. 4 and 5 illustrate an alternate method of producing in quantity measured lengths of webbing strips with fastener attached, ready for final assembly to the tubular framing according to the invention. More particularly, the chutes C-3, (3-4 for supplying the individ ual fasteners (corresponding to the aforesaid chutes C1, C-Z) are disposed just below the strip A of webbing being worked on, and are adapted to provide a rigid support for the fasteners about to be assembled, positioned with their shanks or attaching legs 10 pointing upwardly or toward the under face of the webbing strip. Disposed above the chutes C-S, C4 and to the opposite face of said webbing strip therefrom are a pair of Webbing strip depressers 13-3, 13-4, illustratively having the form of arcuately shaped shoes. Normally, said shoes are raised as in FIG. 4, but they are positively lowered against the webbing strip, preferably in synchronism with the working stroke of the cut-off knife B, to a position as shown in FIG. 5. During the course of their lowering movement, the shoes force the webbing strip against the fastener points 14, as results in the latter penetrating same, similarly to the fasteners being forcibly moved against the webbing strip.

Although the hole-making and forming plungers corresponding to those designated P-1 and P-2 in FIG. 1 have not been shown in FIGS. 4 and 5, it is to be understood that such will be provided if desired or considered necessary. If provided, said plungers will of course work oppositely to the plungers P1 and P-2; that is, they will be positioned above the webbing strip; and they will move downwardly on their working stroke against the upper face thereof, and upwardly on their retracting stroke. Also, said plungers will work through the depressor shoes D-3 and D-4. This alternate method makes possible a greatly simplified chute construction, as compared to that employed for the FIG. 1 method, for example.

Without further analysis, it will be appreciated that the above described method in its various forms achieves the objectives of the invention as previously explained in effective and dependable manner. That is to say, the in vention provides a fully automatic method of producing measured lengths of webbing strip having attached to the ends thereof the fasteners which ultimately secure said strips to the tubular framing of metal frame furniture. The provision of such measured lengths of webbing strip with fasteners attached of course makes possible substantial economies in the costs of manufacturing such furniture in that it saves the heavy labor costs of manually applying the fasteners at the time the webbing strips are assembled to the tubing. It is also to be observed that the herein method makes possible the production of complete webbing strip and fastener sub-as- 7 semblies at a convenient time and location, and their use at another time and location, the webbing strip and fastener sub-assemblies lending themselves to both storage and shipment in quantity.

Of course it is to be understood that the above described methods may be varied appreciably both as to order of steps and detail in the procedures employed. For example, when working on plastic webbing strips, the plungers P1, P2 may be heated so as to heat-seal the threads or fibers defining the hole which they form against raveling, and similarly the knife B may be heated so as to heat-seal the end edges of the measured lengths of Webbing strip against raveling. Or said knife B may be configured so as to pink said end edges of the meas ured lengths of webbing strip, thereby to prevent them from raveling. It is also possible within the scope of the invention to vary the method by completely separating the cutting-01f and fastener-applying operations. For example, the webbing strip may be cut to measured lengths in one operation and the measured lengths fed in succession to fastener-applying means as aforesaid which eifects application of the fasteners to both ends thereof. Again, the ultimate product is the same as those produced by the prior described methods of the invention.

Thus, as many changes could be made in carrying out the above methods without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. In tubular frame furniture manufacture, a mechanized method of pre-assembling T-shaped fasteners made of sheet metal and consisting of an elongated head and a depending fastener leg having appreciable width as compared to its thickness and terminating in an arrowheadshaped point wider than said leg proper to the webbing strips adapted to form the seat and/or back elements of said furniture, which comprises the steps of:

(a) arranging each fastener element relative to a Webbing strip in position such that the fastener head and its leg extend transversely across the webbing strip at a predetermined location along the length of the latter and the leg point is directed towards a face of the webbing strip; forcibly projecting said fastenerleg point through the (b) webbing strip by moving the one towards the other at a speed such that the edges of said point would normally sever one or more of at least the longitudinal threads or fibers of the material making up the webbing strip and thereby weaken said strip;

(c) and just prior to the leg point making contact with said one face of the Webbing strip applying localized pressure against the opposite face of said webbing strip in the general area thereof which is aligned with said fastener point and in such manner as to effect sidewise displacement of the aforesaid threads or fibers making up the material of the Webbing strip,

thereby to assist the fastener-leg point penetrating the webbing strip without substantial severance of said threads or fibers thereof.

2. The method according to claim 1, and the further step of withdrawing said localized pressure generally in accordance with the movement of the fastener-leg point through the webbing strip.

3. The method according to claim 1, wherein two such fastener-to-webbing strip pre-assembly operations are carried out simultaneously, one at a predetermined location adjacent one end of a predetermined length of webbing strip and the other at a corresponding location adjacent the other end thereof.

4. The method according to claim 1, and the further step of feeding the webbing strip and fasteners intermittently to their respective aforesaid positions at which pre-assembly of the fasteners to the webbing strip is effected as aforesaid.

5. The method according to claim 1, including the further steps of:

feeding a long length of webbing strip material from a source of supply thereof along a predetermined longitudinal path with a step-by-step motion; feeding a plurality of fasteners to be assembled along a path which intersects the path of motion of said strip and also with a step-by-step motion;

simultaneously affecting, in the interval between each two consecutive feed motions of strip and fastener, two fastener-to-webbing strip pre-assembly operations as aforesaid at locations along the length of the strip which are predetermined in relation to the length desired in the individual pre-assembled webbing strip elements being produced; and

severing the elongated strip into lengths corresponding to the desired length of the pre-assembled webbing strip elements being produced.

6. The method according to claim 1, wherein said fasteners to be pre-assembled are each arranged relatively above the webbing strip and are disposed with their fastener leg pointing downwardly towards a face of said strip, and wherein pre-assembly is effected by positively moving each said fastener against the webbing strip.

7. The method according to claim 1, wherein each said fastener to be pro-assembled to a webbing strip is arranged at a fixed location below said webbing strip and is disposed with its fastener leg pointing upwardly towards the under face thereof, and wherein pre-assembly is effected by positively moving the webbing strip downwardly against the point of the fastener leg.

References Cited in the file of this patent UNITED STATES PATENTS 1,727,184 Thompson Sept. 3, 1929 2,036,787 Zabriskie Apr. 7, 1936 2,256,634 Webb Sept. 23, 1941 2,395,761 Reed Feb. 26, 1946 2,663,074 Schultheis Dec. 22, 1953 2,781,816 Lawson Feb. 19, 1957 

